Syringe cartridge



March 12, 1929. H. s. cm 1 1,704,936

SYRINGB CARTRIDGE oi izinal flied July 1, 1921 Him l l l l Patented Mar. 12, 1929. 1,704,936

UNITED STATES PATENT OFFICE.

HARVEY S. COOK, OF VALPARAISO, INDIANA, ASSIGNOR TO COOK LABORATORIES INC., A CORPORATION OF DELAWARE.

SYRINGE CARTRIDGE.

Original application filed July 1, 1921, Serial No. 481,997. Divided and this application filed November 25, 1925. Serial No. 71,319.

This invention relates to hypodermic syras a slidable isto lu Whe inges of the cartridge type, and more paris pushed forv iard by the syringe ticularly to cartridges or medicament-disa considerable pressure is imposed on the pensing packages for incorporation in such liquid in the cartridge, causing rapid dissyringes. The invention aims to improve charge through the needle, since the area 55 such devices with a view to preventing or ,of the piston plug is large as compared with counteracting sucking-back tendency, and to the fine bore of the needle. It is desirable provide a practicable and reliable cartridge to have the piston plug of suflicie'nt length which will not be liable to sucking-back acand tightly fitted or under sufficient comtion when the applied pressure for operating pression in the glass tube for effectual seal- 60 the cartridge is released. ing and to maintain the seal during the fluid- A cartridge embodying the invention in ejecting operation. On the other hand if one practicable form is shown for illustrathe thrust of the operating plunger on a tion in the annexed drawings, in which: tight fitting rubber plug or stopper should Fig. 1 is a longitudinal section of a syringe cause forward protrusion of the central body or injection-administering organization conportion of the plug, due to lagging of the taining such a cartridge as an operative peripheral portion of the plu in frictional component thereof; engagement with the glass tu e, then when Fig. 2 is an enlarged longitudinal section the applied pressure on the plunger is re- 20 of a fragment of the cartridge, showing its leased the reflexingof the plug in resuming piston plug being pushed forward by the its undistorted state would create or tend to syringe plunger; create a back-suction through the injecting Fig. 3 is a cross-section on the line 3-3 of needle. It is desirable to avoid such an Fig. 2, looking in the direction of the effect, in order to guard against ossibility 25 arrows. of contamination by drawing bac blood or The illustrative cartridge, comprising a matter from the patients tissue, lest a pracglass tube 12 sealed by rubber plugs or stoptitioner after having administered an injecpers 13 and 14, is shown in Fig. 1 in an intion of only part of the cartridge contents strument which in conjunction with the should make a further injection of the recartridge provides an operative syringe or malning contents in another person, contrary injection-administering organization. Said to good practice. instrument comprises a cartridge-holder 5 Accordingly, the rubber plug 14 is dehaving removable heads 6 and 7. In the signed with a view to minimizing such disbreech head 7 is a slidable plunger rod 8 tortion'by plunger thrust as would cause suck- 35 having an enlarged inner end 9 adapted to 1ngback action by reflexing of the plug when enter the glass cartridge tube and drive the the applied operating pressure is released. stopper 14 forward for ejecting the liquid Moreover, said plug embodies provision to contents of the cartridge through the in'ect- X It an ac ion counter or in opposition to ing needle 10 attached to the fore end 0 the sucking-back tendency. In the specific form instrument. Communication between the shown, said plug comprises an annular body cartridge and needle is established in this 1 1 having a transverse web 14 integral instance by penetration of the inwardly therewith, the web being shown intermediate projecting end of the needle through the the ends of the plug. The annular portion readily pierceable recessed rubber Stopper 14 is relatively thick to provide a sufliciently 13 in the fore end of the cartridge. By stout or firm plug body to be co pressed in means of an intermediate needle enlar ement the cartridge tube and which may be pushed 11, seated in the head 6, the needle is held forward by the plunger bearing against the in place. It will be understood that this rear end of the annularplug. The transparticular organization is merely exemplary. verse web 14 is relatively thin for flexing,

As above indicated, the stopper 14 serves and is preferably thin enough to be quite flexible. In view of the design or form of the plug, the plunger thrust is applied on the annular body, so that there can be no forward protrusion of the central portion of the plug by the thrust of the plunger, even though the plug should initially stick to the glass tube. Moreover, during the fluid ejecting operation, the fluid pressure in the cartridge causes the relatively thin web 14 to bulge or flex backward as shown in Fig. 2, or perhaps even to a greater extent than shown. When the operating pressure is relieved, the resilient web in reflexing or resuming its normal undistended position Wlll cause or tend to cause the liquid to continue its flow through the needle, for an Instant after the pressure on the plunger is relieved. Thus the reflexing action is such as to tend to continue the ejection rather than to cause or tend to cause a sucking-back effect.

The Web or diaphragm 14 typifies a 119- uid abutment yieldable to the internal fluid pressure and the reaction or rebound of which will tend to continue the ejection and thereby prevent or counteract back-suction tendency. Again, the plug 14 typifies a stopper having a cavity with a front resilient wall exposed to the liquid, for the purose stated, such cavity in this instance eing the rear cavity behind the web.

While the plug may assume various forms, I prefer the specific form herein shown, wherein the web 14 is located about halfway between the ends of the plug, or at any rate substantially beyond the rear end of the plug, on which the plunger thrust is imposed. With this form of plug, the plunger head whether of the ordinary flat-faced form or of a recessed form as shown will bear only on the rear annular end of the plug and avoid a forward thrust of that considerable area of the in the annular portion.

If the plunger head 9 has a recess or cavity 15 as shown,'the flexible web 14 of the rubber piston plug 14 could be located at or so near the rear end of the plug that the web when distended by fluid pressure would bulge back into the said recess of the plunger head. Of course the recessed plunplug which is withger head has the advantage that with any form of plug it would concentrate the thrust of the plunger on the rubber plug at or near its periphery, where frictional resistance is set up. However, a flat-faced or unrecessed plunger head is ordinarily or preferably employed in a syringe instrument of the kind shown, and in that event the rubber piston-plug embodying the rear cavity with the flexible front wall 14 exposed to .the liquid unites the advantages of avoiding plunger thrust on the center of the plug and of reflexing in a manner to prevent or counteract sucking-back tendency.

The described piston-plug provides a sealing closure which is more easily compressed and inserted into the glass cartridge tube than a solid plug of the same dimensions and material; and while it adequately seals the cartrid e, it does not stick to the glass so firmly afler a long lapse of time, or if stuck can be more easily released, and pushed forward.

A cartridge embodying a piston-plug of substantially the form shown was ori inally disclosed in my application filed uly 1, 1921, Ser. No. 481,997, now pending, of which this application, in so far as it is based upon said original disclosure,,is a division. Notice is given that a cartridge embodying a pierceable fore stopper such as the stopper 13 herein shown, characterized by .an inwardly facing axial recess which reduces the thickness of the wall to be pierced by the needle and on the annular wall of which the hydrostatic pressure will act radially outward during the fluid-ejecting operation, so as to tighten the hold of the stopper in the tube, is the subject-matter of an invention claimed by me.in my said prior application Serial No. 481,997; and that a syringe embodying such cartridge and associated means including a cartridgepiercing needle or canula, to provide an 1nection-administering organization, is subject-matter disclosed in said riorapplication and in my pending application Serial N 0. 11,707, filed February 26, 1925, as a continuation of an application filed by me April 8, 1921, Ser. N o. 451,68O which syringe or subject-matter is now bein claimed in said application Ser. No. 11,707. Notice is also given that a syringe organization embodying such a cartridge with an instrument of substantially the construction herein shown, the essential parts of which instrument were originally disclosed in my pendin applicat1on Serial No. 540,628, filed Marc ;2, 1922, s subject-matter claimed by me in my endmg application filed August 5, 1922, erial No. 5 9,924.

This application is accordingly for the particular subject-matter described and set forth in the appended claims.

\Vhat I claim is I 1. A dispensing package for liquid medicaments comprising, in combination, a rigid tube; a recessed plug sealing one end of the tube; and a second plug initially at the other end of, the tube and slidable therethrough; said second plug having an annular portion of sufiicient length and thickness to prevent escape of the medicament during sliding thereof, and a thin, pressure-sensitive web coaxial thereof and integral with the annular portion and located centrally of the ends; said web being distended by the hydrostatic pressure of the medicament during GJGCtlOIl.

2. A dispensing package for liquid medicaments comprising, in combination, a conable b a fine canula, and the other end sealed by a slidable plug which dispenses the contents thereof; said plug having a relatively thick annular portion of relative stillness for secure sealing, and a relatively thin web integral with the annular portion and flexed when the hydrostatic pressure within the package is increased as during an injection.

3. A dispensing package for liquid medicaments comprising, in combination, a con-' tainer body of tubular form having a rubber plug located at one end thereof; said plug having a diaphragm'which is sensitive to and distended by the medicament when under the pressure created by dispensing.

4. A dispensing package for liquid medicaments comprising, in combination, a container body of tubular form having a slidable rubber plug initially located at one end thereof and slidable thercthrouglrto dispense the medicament; said plug having a centrally located portion which is sensitive to and distended by the medicament when under the pressure created by dispensing.

5. A dispensing package for liquid medica-ments comprising, in combination, a container body constructed and arranged to permit dispensing of the medicament through a fine canula; and'a resilient plug slidable through said body to effect said dispensing; said plug having the portion adjacent its longitudinal axis provided with oppositely facing cavitiesor recesses so that the plug, if pushed by a syringe plunger, will not create aback suction through the canula when pressure on the plunger is relieved.

6. A hypodermic syringe comprising, in combination, a body having a slidable plunger whose inner end is coaxially recessed; and a medicament containing cartridge inserted in said body and having a slidable plug therein designed to be pushed by the plunger to dispense the contents of the cartridge; said plug having a pressuresensitive web located coaxially thereof.-

7. A hypodermic syringe comprising, in combination, a syringe body having a plunger; and a medicament dispensing cartridge held by the syringe body and having a slidable plug therein constructed and arranged to be distended by the hydrostatic pressure of ejection and to restore itself to its initial undistended state when saidpressure is relieved.

8. A medicament-cartridge for hypodermic syringes comprising a sealed liquid con-- tainer embodying a tube having at one end a closure to be pierced by a canula, and having in its opposite end a plug to be forced through the tube to expel the liquid, said plug having a portion which during the ejecting operation will be distended by hydrostatic pressure and which when the pressure is released will flex in a direction tending to continue the ejection, thereby preventing sucking back tendency.

9. A medicament-cartridge for hypodermic syringes comprising a sealed liquid container embodying a tube having at one end a closure to. be pierced by a canula, and having in its opposite end a plug to be forced through the tube to expel'the liquid, said plug comprising a thick walled tubular body of resilient material and a Web integral therewith located intermediately of the ends of the plug.

10. A medicament-cartridge for hypoder- I mic medicaments comprising a sealed liquid container embodying a tube having at one end a sealing closure to be pierced by a canula, and having in its opposite end a sealing closure comprising a plug of resilient material tightly fitted in the tube and adapted to be forcibly pushed therethrough to expel the medicament,.said plug embodying means whereby the plug if pushed inwardly by a syringe plunger will not create a back suction through the canula when pressure on the plunger is released;

11. A syringe cartridge comprising a sealed liquid container adapted for communication with an injecting needle and embodying a tube with an inwardly displaceable piston plug, said plug constructed to receive and transmit plunger thrust applied against its rear end and embodying in ad- Vance of its rear plunger-engageable portion resilient means exposed to the liquid in the cartridge and yieldable to the internal fluid pressure during the ejection and which upon release of the applied operating pressure will react on the liquid in a manner tending to continue the ejection and thereby prevent sucking-back action.

12.- A syringe cartridge comprising a sealed liquid container adapted for communication with an injecting needle and embodying a tube with a rear sealin stopper of elastic or yieldable-material adapted to be pushed inward by a plunger for ejecting the liquid through the needle, said stopper embodying in advance of its rear plungerengageable portion a cavity with a flexible front wall exposed .to the liquid in the cartridge, whereby as the stopper is pushed in ward the said wall is flexed rearwardly by the fluid pressure in the cartridge and when the pressure applied by the plunger is released the said wall reflexes in a direction tending to continue the ejection.

13. A syringe cartridge comprising a sealed liquid container adapted for co unication with an injecting needle and embodying a tube with a rear sealing stopper of elastic or yieldable material adapted to be ushed inward by a plunger for ejecting the plunger in a manner which would tend to iquid through the needle, said stopper emcreate back-suction by reflexing when the bodying an axial cavity closed at its front pressure on the plunger is released. 10 end such as to prevent forward protrusion In testimony whereof, I have signed my 5 of the central portion of the stopper by the name to this specification.

thrust of the operating plunger and thereby to minimize distortion of the stopper by the HARVEY S. COOK. 

